1. Field of the Invention
This invention relates to an image recording device.
2. Description of the Prior Art
It has heretofore been a common practice in the color image printing that, in making a screen plate, the angle of a dotted screen for the screen plate is varied for each and every color component. The reason for varying the screen angle is to prevent Moire fringes from occurring due to synthesis of the component colors. For example, the screen angle is varied with respect to the horizontal scanning direction such that a magenta plate is at zero degree, a yellow plate is inclined by 15.degree., a cyan plate by 30.degree., and a black plate by 60.degree.; or a magenta plate is inclined by 15.degree., a cyan plate by 30.degree., a yellow plate by 40.degree., and a black plate by 90.degree.. Further, for varying the screen angle, a contact screen is used. This contact screen, however, has varieties of disadvantages including that its service life is short.
As a device for varying the screen angle without using the contact screen, there is a screen-covered scanner which imparts to a light source a light modulation corresponding to the contact screen to thereby prepare a screen-dot image without use of such contact screen. In order to set an arbitrary screen angle in such device, an auxiliary scanning is mostly conducted at a particular angle with respect to the principal scanning. For instance, as disclosed in Japanese Patent Publication No. 55-31462, an arbitrary screen angle is set by conducting the auxiliary scanning through deflection of an oscillatory mirror in a galvano-meter, in a addition to the principal scanning by revolution of a mirror.
Owing to necessity for the auxiliary scanning by the oscillating mirror, etc., however, the above-mentioned conventional device has disadvantages such that it is expensive, and that adjustment and handling of the mirror are complicated and troublesome.